Significance of Ticks and Tick-Borne Pathogens

Ticks (Acari) are voracious bloodsucking ectoparasitic arthropods infecting a vast variety of host around the globe such as mammals, birds, reptiles and amphibians.

Significance of Ticks and Tick-Borne PathogensTheir distribution varies from tropics to subarctic areas with greater species diversity in tropical and subtropical regions. Tick bite can transmit a versatile range of pathogenic organisms including viruses, bacteria and protozoa other than causing tick paralysis, toxicosis and allergic reactions.

Ticks are divided into four families namely Argasidae (soft-bodied ticks), Ixodidae (hard-bodied ticks), Nutalliellidae and Laelaptidae. More than 850 species of ticks belong to these four families. Ticks and tick-borne infections cause major economic losses to livestock industry by not only reducing the live weight gain but also by transmitting various pathogens.

Global warming and increased contact between host and parasites has led to the ever-increasing tick population and ultimately, to wide spread ticks and tick-borne infections. Ticks of veterinary and public health significance have been classified into two main families; hard and soft ticks.

In tropical and subtropical countries like Pakistan, India and Bangladesh other than climatic conditions, poor management practices further deteriorate the situation. They cause heavy economic losses to livestock industry due to their notorious blood sucking habit.

They have deleterious qualitative and quantitative effects by influencing body condition, physical performance, wool and hides quality, blood profile, productive and reproductive capability of domesticated ruminants.

More than 200 species of known tick fauna are important from human health point of view because of their role both as an ectoparasites and as vector of pathogen transmission.

Ticks belonging to family Ixodidae can transmit a wide variety of pathogens i.e bacteria, virus, rickettsia and protozoa to both animals and humans. Exotic breeds, malnourished and stressed animals show high susceptibility towards tick-borne infections, becoming carrier for the rest of their lives.

Tick-borne pathogens

In topical, subtropical and temperate countries like Pakistan and India, other than climatic conditions, poor management practices also favor the likelihood of tick-borne infections. On the whole, exotic breeds stressed and underfed animals and those living in poorly managed habitats are more prone to ticks and tick-borne protozoan infections.

Ticks of family Ixodidae can transmit various species of rickettsia and protozoa including piroplasma spp., Anaplasma spp., Bartonella spp., and Rickettsia species. All these parasites are of great veterinary and economic significance as they not only cause high mortality and morbidity in cattle, sheep and other small ruminants but also cause huge economic losses.

Ticks belonging to family Ixodidae can transmit a wide variety of pathogens i.e. bacteria, virus, rickettsia, and protozoa to both animals and humans. In tropical and subtropical countries like Pakistan, India and Bangladesh other than climatic conditions, poor management practices further deteriorate the situation.

Exotic breeds, malnourished and stressed animal’s high susceptibility towards tick-borne infections, becoming carrier for the rest of their lives.

More than 200 species of known tick fauna are important from human health point of view because of their role both as an ectoparasites and as vector of pathogen transmission. Ticks of veterinary and public health significance have been classified into two main families; hard and soft ticks.

They cause heavy economic losses to livestock industry due to their notorious blood sucking habit. They have deleterious qualitative and quantitative effects by influence body condition, physical performance, wool and hides quality, blood profile, productive and reproductive capability of domesticated ruminants.

Role as vector

Ticks play role as a vector and responsible for the transmission of many of pathogens to animals and humans. Ticks are important from both human and veterinary importance.

Ticks also transmit some viral, protozoan and bacterial pathogens causing diseases like hemorrhagic fever, anaplasmosis, theileriosis, ehrlichosis, and babesiosis in dairy and meat animals. Tick can also play role as a reservoir of infectious agents like Pasteurella multocida, Brucella abortus and Salmonella typhumurium.

Impact of climate on tick borne diseases

Change in climatic conditions may have great impact on all these stages as well as their interactions. Furthermore, change in the climate and length of different seasons will affect directly the tick survival, development and activity. However, there is not enough evidence that rise in temperatures results into a greater profusion of ticks.

Over the past two decades, tick-borne diseases have increased and now constitute a major health problem in many parts of Pakistan. Principal amongst these are tick-borne encephalitis (TBE) and Lyme borreliosis (LB), both zoonoses caused by agents transmitted by Ixodes ricinus and I. persulcatus.

Effect of Ticks on milk production

Progressive economic losses to livestock industry is infestation including ticks species Hyalomma 31.25%, caused due to parasitic diseases which are responsible Rhipicephalus 17.93%, Amblyomma 4.61% reported by for lower level of productivity in affected animals. Tick had borne disease effect the cattle improvement Ticks are ectoparasites of mammal’s bird and reptiles of meat and milk production in Italy Sicily.

The Genus they are obligate, blood sucking arcanides ticks are Rhipicephalus (formerly Boophilus) hard ticks found in vector of number of disease including Therelichiosis, Australia, America, Asia and Africa.

Now a day’s Anaplasmosis, Bebesioses, Typhus, Enrlichiosis, etc. Rhipicephalus (formerly Boophilus) are included in Ticks have haemotophagous mode of nutrition, Rhipicephalus, are enormously important for the livestock their blood sucking habit is rapacious so they industry in the world.

Rhipicephalus (formerly Boophilus) impoverishes the hosts due to their requirement of lot of specie are one host hard ticks affected mainly cattle blood for rapid development. Due to heavy infestation of including buffaloes, cows, antelopes, deer, sheep’s, ticks, cattle takes more feed for fulfillment of requirement goat and horses.

Birds cats dogs and humans do not of parasite, then it effects the retarded growth of young affected by Rhipicephalus (formerly Boophilus). Some ones, they may remain internally weak stunted, thin and important species of Rhipicephalus (formerly Boophilus) production of milk in dairy cows became greatly reduced are Rhipicephalus microplus is called cattle ticks also as compare to winter during the summer ticks called as blue ticks.

Rhipicephalus annulatus called as prevalence higher more than one genera of ticks were American cattle ticks and Rhipicephalus decoloratus. fed on the livestock species.

In cattle’s and buffalos, It causes the significant economic loses to the livestock genus Hyalomma most prevalent followed by those industry in turn of production of meat, death of affected belonging to Rhipicephalus (formerly Boophilus). animals, decreased m milk yield and damaged hide.

Control strategies

Tick-borne diseases are common occurrences in both the medical and veterinary clinical settings. In addition to the constraints related to their diagnosis and clinical management, the control and prevention of these diseases is often difficult, because it requires the disruption of a complex transmission chain.

Involving vertebrate hosts and ticks, which interact in a constantly changing environment. We provide a contemporary review of representative tick-borne diseases of humans and discuss aspects linked to their medical relevance worldwide.

One Health approach

The integrative thinking on human and animal health comes from ancient times. More recently, the role of companion animals and the vector-borne diseases they share with humans have been conceptualized with a One Health approach.

Similarly, to other vector-borne diseases (e.g., malaria, leishmaniasis), TBDs may be difficult to control due to their complex epidemiology that may involve different tick vectors and animal hosts.

Veterinarians and physicians have long dealt with TBDs in their daily routine, following parallel, but often non-convergent pathways. It is now clear that an integrated approach is required for the control of TBDs, particularly for those of zoonotic concern.

It is necessary to unify the animal and human branches of medicine towards a better management of this important group of diseases, filling the gaps of communication between physicians and veterinarians to accelerate diagnosis, to expedite treatment decisions and the implementation of preventive measures.

Waqas Ahmad

Ph.D. Scholar University of Agriculture, Faisalabad

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